ATG5 and osteosarcoma: We further observed that positive expression of TSSC3 and ATG5 was significantly associated with an earlier Enneking stage and there were markedly lower metastasis and recurrence rate (7.1 and 14.3%) for positive ATG5 expression compared to negative ATG5 expression (66.7 and 33.3%) in TSSC3(+) osteosarcoma; however, these differences were not statistically significant (Additional file 2: Table S5).